I have been using a DX7 almost since it was announced. No problems at all. Recently I replaced a power system that had done about 70 hrs in the air with only few new bearings and a new shaft but basically the setup owed me nothing. I replaced it with an eMax 2810 (5mm shaft) and a 40/50A eMax ESC with a UBEC (switched) and have started to have problems. My old DX7 also owes me nothing so I thought a new radio might be a good start. I have a heap of 6 channel Orange receivers (2 with slaves), an AR6100e, and an AR7000 (with slave).

The big question now, which radio ? I'm basically a fixed wing sport/park flyer. 7-9 channels are fine, $s are not much of an issue for the TX but 8-10 RXs would break the bank if I went DSM2 or DMSS exclusively. Get the picture ?

So feel free to jump in and tell me which way to go, currently I favoring JR (like 9503 or something). SD card is almost a prerequ. I value a quality build and I hate to crash if my thumbs are not at fault.

If an SD card is a prerequisite then you're stuck with the newer JR (X series), Spektrum or Futaba.

Hitec doesn't have an SD, nor does the Turnigy/FlySky.

You've identified one very important aspect though -- and that's the cost of receivers being a *major* factor if you've got multiple aircraft.

You could convert your DX7 to FrSky -- I did that for a guy in our club and he's very happy with the results -- but still no SD card.

If you go the 9X way (with ER9X software) then you'll be able to use the standard 2.4GHz system ($9 receivers but no failsafe) or the FrSky system ($20 receivers with diversity and failsafe). You're still stuck with only 16 model memories (8 with the standard firmware), no sliders and no DS card though.

It seems to me that you're after two main criteria:1. backward compatibility in order to limit the overal cost2. future flexibility.

If that is the case, then using a 9x box that is set up for DSM2/DSMX compatibility as well as having the option of FrSky DJR Tx module seems to answer both of those requirements.

Couple that with the ER9X FW and you've got a package that gives you plenty to work with. The EEPE S/W that comes with ER9X means the need for an SD card is substantially mitigated (IMHO). I can't envisage flying more than 16 models in a single session! But then again, i only have one model (so far) ... so what would i know

Finally - the ERSKY9x replacement mainboard (currently in beta test phase) or the Gruvin alternative give the 9X a future in terms of additional features/capabilities that appears only limited by your imagination.

Personally i see no rationale in spending 5x what i need to for the above setup and get a name brand Tx/Rx package. I'd rather spend that money on other things!